Step 4.

Shared posts with large preview images have been getting better click-throughs than small thumbnails posts or just plain text post recommended in the past.

After your fans share your promo, it will be posted on their wall, with an end result like the image below

Type or paste the desire URL where your image is hosted. Your image must be hosted on a secure server like Dropbox, OneDrive, Google Drive, etc…

Use images that are at least 1200 x 630 pixels for the best display on high resolution devices. At the minimum, you should use images that are 600 x 315 pixels to display link page posts with larger images. If your image is smaller than 600 x 315 px, it will still display in the link page post, but the size will be much smaller